Hi,
You can use the same fix that was given by Acrylian for the subject
Update 1.6.3 - Albums not listed anymore,
add the line of code :
require_once(dirname(FILE) . '/template-functions.php');
after :
require_once(dirname(FILE) . '/functions/functions.php');
in the file :
admin-function.php
I solved the problem this way.

@hermor: Thanks, but unfortunately that's not what solves my problem with the image sorting not showing up in version 1.6.4. Even with this fix, the image sorting doesn't work in 1.6.3, and it doesn't in version 1.6.4 where the fix is already included in the core file.

@fneumeier: I am really not aware of changes regarding image sorting from 1.6.2 to 1.6.3/4 that would cause this. Please send a direct mail via https://www.zenphoto.org/pages/contact/

We recently also upgraded to 1.6.4 and has the same issue. May I know if there's a resolution for this?

The temporary solution is documented above. There will be a fix in the coming 1.6.5 release of course. But it is not yet in 1.6.5a because there are a few changes ahead that will be related to this fixing this differently.